This invention relates to a packaging machine and particularly a machine for partially or totally enclosing articles in web stock.
Machines for packaging articles in polymeric or other web stock are well known and widely available. They are primarily used to partially or completely enclose articles in film or web by joining a pair of web panels (which may be the upper and lower layers of a folded web), at the spaces between the articles being advanced. This is typically done by a transverse hot wire or element that shifts vertically to an anvil to seal the web panels. Sometimes the packaged articles are subsequently put through a film shrinkage step. There are machines which perform satisfactorily for this purpose, but such have definite limitations.
One limitation of present equipment is the minimum size of the articles which can be dependably packaged. If the article becomes too small, it will drop into the gap at the sealer or otherwise hang up where the transversely reciprocable sealer and the anvil are located. Another problem area arises because the same area of the anvil is engaged each time, causing eventual wear thereof with consequential defective sealing.
Another limitation involves the complexity of handling articles of different sizes. Changeover of available machines to packaging another size article requires machine shutdown, component changes and/or tricky adjustments during shutdown, and restart in trial and error fashion.